Happy Birthday, Castle
by ifonly13
Summary: It's no joke - April 1st is Castle's birthday.


_**Happy Birthday, Castle**_

* * *

><p>"Good morning, Detective," he says in greeting, drawing out the words as he set down the expected coffee to the side of her keyboard with a quiet snap. He sits, his own cup resting on his thigh, watching the smile sneak onto her face as she reaches for his offering.<p>

Kate's fingers curl around the cardboard sleeve, pulling at the little lip where the sleeve ends. "Morning, Castle." She takes a tentative sip of the coffee, the liquid burning off some of her taste buds in the process. "Looking awfully chipper this morning."

"I guess you could say I'm chipper, yes. Though that sounds so British," muses Castle. "Let's say 'happy,' or 'excited,' or 'over-the-moon,' okay?"

She nods, trying to hide her growing smile behind the coffee cup's lid. "What's put you in such a marvelous mood? It's April and it's raining."

"Well," he says, slipping easily into storyteller mode. "The day started with me being kissed awake by a beautiful woman. The same woman then made me French toast in bed before she disappeared into the sherbet-colored sunrise."

"Except it was raining this morning," Kate reiterates, ignored as he continues his tale, "and the sky looked nothing like sherbet."

"My daughter called even though it was, like, four-thirty in California."

"That was sweet of Alexis."

He hums in agreement. "Yeah, it was. Anyway, I'm just saying that my day's been pretty fantastic thus far."

Kate tosses a grin at him. "Remember, Castle, what day it is." His brows draw together in confusion. "April Fool's Day. Bound to include a few surprises."

She knows the other meaning behind the day, of course. He had always made a point of insisting that the spirit of the wacky holiday, all practical jokes and bad one-liners, had been infused into his very being. Kate really could not argue with his reasoning; every behavior of his had the undertone of April Fool's Day in it. How much of that was "in his blood" as opposed to the man himself amping up his natural charm and charisma had yet to be decided.

"Well, not too many, I hope," he sighs, propping his chin on his fist. "I'm old. My heart can't handle too must stress."

"What about excitement?" she asks, not looking away from the computer screen as she works through a game of Minecraft – she's been trying to figure out the trick behind the confounding game and she's fairly certain that she has a handle on it now.

Castle sits back, running a hand over his head with a groan. "That too. I can feel my heart weaken at even the thought of a murder."

As if his words were able to trigger worldwide events, the phone on Kate's desk rings out, breaking through the buzz of activity on the floor. She cradles the phone in her shoulder, still clicking away at squares on the board of the online game as she answers the call.

Castle can hear a little bit of the conversation as he leans closer to her ear. He has never been able to understand why she doesn't just put the phone on speaker; it would make hearing the details so much easier. He suspects it has something to do with her actually enjoying the feeling of him crowding her but he knows better than to voice such opinions.

"Looks like you'll have to harden your heart, Castle. Got a body on the LES." She gets up, her chair spinning as she pulls her jacket off the back and swings it on. When Castle doesn't move, Kate narrows her eyes at him, giving him a little kick with the toe of her shoe. "Come on. Body. Us. Now."

He springs up, grabbing her coffee that she left on her desk as he follows her over to the elevator. "This is not the birthday present I was hoping for."

Kate smirks, taking the coffee and running her finger along the edge of the plastic lid. "It's your birthday? I had no idea."

"Oh, that's just mean, Kate."

* * *

><p>The conference room is crowded and some of the people have spilled out into the precinct bullpen. Some of them were there just for the free food and beer. The ones that really care about Castle were sitting around the scarred conference table.<p>

He has taken the seat at the head of the table despite the fact that it also held the most uncomfortable chair out of the lot. Kate had made a comment about his ego as he had settled into the chair, shifting every two seconds in an attempt to find a comfy position, before she grabbed a beer and sat a few seats down in her favorite of the mismatched black desk chairs.

"Here, bro," Esposito says, sliding a wrapped present down the table toward Castle. "From Lanie and me."

Castle grabbed the box before it fell off the table, setting down the beer bottle. "Ooh. Co-gifting. Are we official now?" he asked, eyes darting between the two.

Lanie bit into a tortilla chip after dipping it into the salsa bowl. "Maybe we just didn't think you were worth two presents, Castle."

"Sticking with my idea," he mutters, sliding a finger under the wrapping paper.

He immediately replaces his old phone case with the gift from Lanie and Esposito, a hard grey case with a little NYPD seal, the words 'Assistant Volunteer Homicide Detective' written in the same navy blue as the seal. "Oh my goodness, guys! This is officially the best present ever."

His eyes dart toward Kate but she's busy typing into her phone, eyes averted, the beer bottle tucked into her elbow. Her present is missing from the small pile on the table and he didn't want to read into it. So he grins as he snaps the case on, wiggling the phone between his forefinger and thumb. "Beckett, I've got a badge now."

Kate looks up, a brow arched as she studies the iPhone case. "All official now?"

"You bet," he says.

"Good. I've got paperwork for you waiting out on my desk," Kate says with a smile. "Go get started."

He frowns, pocketing the phone. "Nevermind."

She can't help but notice his eyes searching the table for another present. He's going to have to wait another few hours until the end of shift until he gets that one.

* * *

><p>It's been over an hour since she said she'd be back. He's not starting to lose faith in her, he tells himself as he put the chicken parmesan into Tupperware and stashes it in the refrigerator. She said she'd be here tonight, that she just had some things to finish up at work and that it wouldn't take more than thirty minutes. Traffic could only be blamed for so much of the delay.<p>

"She'll be here," he whispers to himself as he sits on the couch, kicking his feet out to cross on the coffee table, nudging aside a Grafton novel he's been working through in his free time. "She said she'll be here and she'll be here."

Still, the seed of doubt had been planted and he could almost feel the roots starting to branch out. What if she didn't show up? Would calling her be overstepping, even if it was just to see if she was still alive?

No. Do not call her. She'll show up.

He sat back and hit the play button on the remote control. He had been on a classic movie kick and had been watching _Notorious_ in half hour intervals between cases, sleeping, and writing. Castle figured he'd need to re-watch the movie in order to get the nuances of the plot down; watching in pieces sort of ruined the flow.

Alicia and Devlin were alternating between murmuring quiet words, pressing their cheeks against the other's, and engaging in kisses that lasted all of three seconds when he heard the front door click shut. He didn't pause the movie as he heard her bag drop onto the hardwood floor. He also didn't watch as she skirted the room, glancing over at him as she walked into the study.

Castle sighs, letting his head fall back against the cushions of the couch. Crap. She looked tired and he could sense frustration just from the way that she walked. He screwed up, ignoring her. He had to fix it before it blew up in their faces.

He pushes up off the couch just as she rounds the corner of the study, silhouetted in the gentle glow from the lamp in the corner. "Kate, I'm…"

Words failed him. They got lumped up in his throat. Because she was wearing the same white shirt she had on all day. Just the shirt. It was one of his – she had become increasingly fond of stealing button downs from his part of the closet, belting them and rolling the sleeves up to her elbow – but this time the sleeves were down past her fingertips, the cuffs unbuttoned. Against the crisp white, her thighs were an impossibly warm cream that didn't end until the bright red flash of her toenails as she curls them under her feet.

"Uh…" he starts, blinking and trying to swallow that clog of words in his throat. But the only thing that seemed to manage getting from his brain to his mouth was another "Uh…"

"Happy birthday to you," she sings, stepping into the living room. "Happy birthday to you."

She places a knee on the left of his thigh, straddling his lap as she pulled the lapel of his shirt in between her fingers. Ducking her head, Kate let her nose brush past his. "Happy birthday, Mr. Castle," she murmurs, lips impossibly close to his but he's too stunned to make a move for them. "Happy birthday to you."

Then, finally, she let their lips meet.

His hands inch up from their spot on the cushions to grip her waist, sliding the white fabric up to bare her hips. "God, Kate," he managed, mouth still against hers.

She rocks forward, breaking off with a laugh. "Sorry, but I didn't think this present would be appropriate to give you in the precinct this afternoon."

Castle reaches up, cups the back of her head to pull her back down to his lips. "Good decision." His fingers trail down her collarbone, opening up the first of the two buttons that she had done up, exposing the curve of her breast. "I don't want anyone else seeing this. Seeing you. You know why?" he asks, eyes darting up to hers for a moment, just long enough to see her eyes flutter open. "Because you're mine, Kate."

Her protest at the ownership turns into a strangled moan when he set his mouth to her breast. She arches away automatically and his arms come to wrap around her, holding her in place as he nudges the fabric of the shirt away. Kate shot her arm out to brace on the back of the couch, a breath huffing out as his lips drift further south, tracing over the curve. His other hand is playing along her thigh, squeezing the muscles lightly.

Determined to regain control of her surprise, Kate pushes back away from him, placing her feet on the ground again. "Well, that's that. Happy birthday, Castle."

Kate makes it to the doorway of the study before she's pulled back against Castle's chest. "Trying to get away from me?" he murmurs into her ear a second before he nips at her neck. "Not very polite of you." His fingers are busy undoing the last button and slipping his hand under the fabric and letting his palm skim over her waist.

"Gotta fight for me," she sighs out, her head tipping back onto his pec as he nibbles his way down the column of her throat.

"Is that how this works?" He takes a step forward, waits until she moves as well. "I have to work for my present?"

The vibration of her hum reaches his lips, settled now at the curve of her shoulder. "Well then…"

She shrieks when he spins her around and lifts her up onto his shoulder, an arm locked around her knees to hold her in place. "Castle, put me down!" she shouts, twisting around so she can rap her knuckles against his head. "Now!"

"Oh, I don't think so," he says, walking into the bedroom and kicking the door closed with the heel of his foot. "You're not allowed to leave me like that when you're wearing… that."

"That?" she manages between breaths, labored from her being upside down. "What?"

Castle tosses her onto the bed, tugging her ankle so she slides toward him. "My shirt. Which I am now going to rid you of." He grabs the sleeves, one by one, and pulls them down her arms, tossing the shirt over into the corner where it catches on the lamp and hangs there.

She's left in mismatched underwear and bra, one forest green, the latter pale pink. Kate hooks her leg on his hip, urging him toward her. "Now what?"

"Well," he starts, leaning over her, his arms on either side of her head, "I think I'm wearing too many clothes."

Kate reaches up, twisting her hands in his sweater. "Let's fix that." When she pulls at the sides of the shirt, he sits back enough for her to yank it over his head, throwing it in the same direction as her shirt. She rakes her short nails down his chest. "Mmm… Much better."

He dips his head down, biting down lightly on her shoulder relishing the gasp that the motion draws out from her. "Still too many clothes."

So she snakes her arms down between them, working at the button of his jeans. "You're awfully picky."

"I'm allowed to be," he reminds her. "It's my birthday, remember?" As she fights the denim down over his legs, Castle is busy fumbling with the clasp on the back of her bra. "God, do you women design these things to discourage us?"

"Duh," she says, using her feet to shove the jeans off past his feet. Then she swats his hands away. "Don't break this one!" Kate unhooks the back before he pulls the straps over her arms.

"Now you're being picky. I'd buy you a new one."

Her protest that she can buy her own underwear is forgotten as he pressed a kiss to her mouth, trailing a heated path down her throat to her collarbone. His hands grip her sides, anchoring her to the mattress even as she tries to arch up to bring more of her skin into contact with his lips. They travel down over the curve of her breast, skimming over the top to continue down to her stomach.

"You're teasing," she gasps, hands tangling in the sheets.

"Taking my time." He hooks his fingers in her underwear, shimmying them down over her legs. The green fabric goes the same route as the shirts and pants. "There's a difference." Castle snags her foot, pressing hot, open-mouthed kisses to her calves as he travels up past her knee to her thigh.

She squirms, a hand reaching down to thread through his hair, tugging the strands lightly. "Castle…"

"What?" he breathes across her inner thigh, the warm air curling against her already heated center.

"Do something already!" she shouts, giving his hair another fierce pull. When he just studies her for a moment, Kate growls. "Please."

He crawls up, still creating a path of kisses up her stomach, between her breasts, and back up to her mouth. "You're pushy for a present, you know."

"I'll take the present back if you don't get a move on."

"Why? Got another boyfriend you need to meet tonight?" he teases, feathering his lips over the shell of her ear, his cheek pressed to hers.

Kate turns her head, capturing his lips. "Yes. Antonio and I have a date in thirty minutes, so…" Her voice goes from joking to a strangled gasp as he slides his finger up into her.

"Still thinking about Antonio?" he murmurs against her ear.

"What if I said 'yes'?"

"I guess I'd have to do something like this then." He shifts, letting his fingers slip over her, swallowing her soft moan. He doesn't give her a chance to relax before he pushes inside her. "And now?"

"God, Castle," is her response as her fingers scramble for something to hold onto. She finds the sheets, wrapping her hands up in them as an anchor.

Her staccato breaths make him grin. "I'd have been worried if you said 'Antonio,'" he says, feathering a kiss over her lips, a marked difference from the heat between them.

Kate moves her hands from the mattress to his back, using her short nails to draw a gasp from him. "Stop talking," she grinds out. She almost – almost – regrets the request when he pushes into her completely, twisting his hips just enough to cause a tiny, high-pitched whine to escape from her throat. Kate bites down on her lower lip, trapping the rest of the helpless keening behind her teeth. She tried to inch her foot up his calf to change his angle but she can't find the strength. "Castle, please," she whimpers.

"What?" he returns with far too much vocal ability, only slowing his movements minimally. "What do you need, Kate?"

"Something…" she sighs, trying to tip her hips but not finding the right position. "Don't know…"

Castle wraps his arms around her waist, the motion tilting her hips enough for him to find the right spot. He can tell from the way that Kate's mouth drops open on a huffed breath. "There it is," he murmurs, pressing a kiss to her neck. "You're so close."

"So do something about it!" she shouts, fingers holding onto his biceps in an attempt to give as good as she's getting.

With another five collisions of their hips, Kate tips over the edge with a strangled sob. Except he didn't stop and let her catch her breath, instead continuing to slam into her. "Castle, I can't… Just…" Her lips skim over his cheek, a silent plea as she feels her body start to shake as he draws this release further and further than they've gone before. "Please, Rick."

He captures her lips, taking the last of her breath. "God, I love you, Kate," he manages, mouth skating over her ear.

Kate turns her head to brush her lips against his. "Happy birthday."

* * *

><p><strong>Note from Logan: Well this only took me over a month to write. Was it worth it?<strong>

**Anyway, happy birthday to our favorite bestseller!**


End file.
